Collins



May 2, 1950 D, COLLlNs 2,506,543

AUXILIARY CONTROL FOR HYDRAULIC BRAKES Filed March 15, 1948 2Sheets-Sheet 1 @MQW D. COLLINS AUXILIARY CONTROL FOR HYDRAULIC BRAKESMay 2, 195o 2 Sheets-Sheet 2 Filed MarCh 15, 1948 ||||||||fl||| IINVENTOR. .Peay/as Colli/2.5'

Patented May 2, 1950 OFFl-CE ,AUXILIARYZ CONTROL vIO-R HYDRAULIC"`vBRAKES 'This inyentionrrelatesf-fto 'dei/'roesv for affordingauxiliary control for hydraulic brakes and isconcerned more particularlywith improvements'in the:4 control "-disclosed in my prior 'Patent' No.

" According tomyjprier inventionitis ynecessary that the yvehic'leoperator reta-in` the control I'vent `closed by: the application 'ofythe hand @thereto forfasrlong aperiod Vasgit may be de-...oome'theselldisadvantaees .and torprovde anerrengement wherein onlythe`V momentary apolisuch adjustment as to maintain .thebr'akes appliedvwith the. .desi-red .forcefor .as `lorie e period as desired withoutnecessitating-.the lons,- conl Ajfllrther. object is theyprovision Y ofmeans lop- Eerative junder i the controhof 'the engine` throttleyalveforrenderine theauxliary.coritroliheffective'. and Hrestoringv .thebrake -Systemn to normal condition in. ywhich the brakes v.are operablein. a

.useful manner .underithooontrol of thebraike medal.

Y `In the accompanying drawinawhereinanirni Figure .1Y isan assemblyview'showing the auxiliary n, control1 'mechanism 1 ,cornbinechwith aconventional,hyclraulic' brakingsystem andthrottle valve of al motoryehicle.

Figure 2A is an. enlarged :vertical sectional vView .of a .portion ,of`the.master ylndei". valve device lmein-the. Serv0emotor, the 4partsbeing .shownmin nthe"position oocupiedwhen the', auxiliary .controldeviceis ineffective.

.liielure 3 `is an enlargedy detailed.sectional Lview of the;deyicecontrolling, operationof theservoi motor.

, Figure-Lisa.fragmentaiyside vie-W oa por- ,.tion of lthegenginershowingthe throttle valve -and its lrelation to:theservo-motor.controldevice.4v

1 Referring'ito lthe;.drawinaindetail, .and {car- I :ticularlystothose-parts which-.gare ,disclosedr in my prior natentabove"referredfto,the oi1. res er voirs VI has .the. :usual: partsvcommunicatingwithfende-Supplying oilifto theimaster cy1inder1112 of thefbrake`applying-mechanism; andfthefoilzunder pressurefis`dischargeclf'.through'-portail into the "Eil 4o openings of 'the.casing lt-l.

cylinder`s;` two'of which-are shown jat 1, 1,' for the vapplication ofthe brakes.

The auxiliary control mechanism whchincludes a vacuum ,operatedVservo-motor Yindicated as'a whole byr the letter S, and a valve-deviceindicated as a whole bytheletter V, is interposed Abetween V`thedischarge port 3 of the master-#cylinder and the brake-cylinders;l twoof which are indicated `as l, l.

The valve device, Yas best seen in Figure'lis connected to the mastercylinder at its discharge end by means of a threaded nipple 8 that -isscrewed into the' boss forming the discharge port 3 of the mastercylinder. The nipple is rigidly mounted upon an'vextension 9 of onesection l0 ofthe valve-casingpthe other section Il of the casingproviding an interior chamber for aeXi- .ble and resilient diaphragm i2that is clamped between the two-=sections of the casing. In Figure 2 itwill be seenY that when lthe brake pedal is depressed, the piston 5 ismoved to force oil undenpressnre from the-master cylinder 2, througntheport i3, thence through a tapered valve-seat M, andthencethe cil isforced down 'through an outlet portI at the under side of the extensionand through al pipe-connection I5 to the oil pipel E and 4the brakecylinders l, for an application cf the brakes.

After the brakes have been applied,-passage lof voil under pressure fromthe masterv cylinder through the valve seat Et to the brakepipe 6, mayibe cutoiionthe purpose of retainingVV the applied -brake-pressure-'inthe brake cylinders, lthus holding the brakes applied. This cut-01T.between the master-.cylinder and the brake-cylinders-'is accomplishedby 'the use of va needle valve, or tapered control Valve Itfashioned'eon .one end v'of a tubular stem il, Whichis-externallythreaded at ,l, andmounted'to slide in central The stern also Vpassesthroughv a central opening in the -idiaphragvm 52, and-bymeans l-of apairA of ylock nuts E9 and 2U screwed von the threads l8 at oppositesides` of the diaphragmthe stemmis `mounted in the diaphragm for aslide-piston movement in its bearings in the -valvecasing'and *in theextension@ of vthe''cas-ing.

"Y'Thetubular stem is fashioned with a longitudif nally extending bore`or passagev 2 l aligned with -tthejrlongitudinal Iaxis of the mastercylinder ft2, Aand the outerfendof -'this lpassage-is closedbysuitable'means, as f a threaded tubular heath-22 oiel -casing-I 23.??Thethreaded tubular ulcead'lis lscrewed*into-a socketat #the outer endofi-the A*the* latter Aprojects Atlfirough-4 the valvevcasine'fi and`1the`l Aswitchwaitingcontainsl a yfluidpressure operated circuit-rnakeror switch -ifor the? -iisual Lstop-light that `is carried-at the Nrear`of th aut motive-vehicle; Iconnections -fromfthe The tubular valve-stemis fashioned with a transversely extending port 26, which affordspassage of oil from the bore 2| to the interior of an oil chamber 21 inthe casing I 6, at the brake-side of the casing. Thus it will beapparent that oil through the reduced bore 2l and port 26 having asub-normal pressure, or a pressure below that of the braking pressure isconstantly accessible for operating the stop-light switch, and also forextending the subnormal pressure against the brake-side of the diaphragmI2, as a safety measure, to assure unseating of the valve in the eventthat it is closed for any reason, when the brakes are to be applied.

In the event the auxiliary control mechanism is to be used as ahill-holder after the brakes are applied, the normally open valve ismoved to its seat to close communication from the brake pipes andthereby retain the pressure already applied in the brake-pipes 5 and inthe brake cylinders 1. This closing of the valve against ten sion of theresilient diaphragm I2, is accomplished through the action ofdifferential fiuid pressure operating in the servo-motor S, and throughlever connections with the valve-stem l1. The servo-motor is preferablymounted above and rigid with the valve casing |-I l, through the use ofa supporting bracket 28 fastened to both the valve casing and theservo-motor, and the motor includes a flexible diaphragm 29 mountedwithin the casing 3D. The spring 29' urges the diaphragm to the right inFigure 2 in the absence of a vacuum at the left side of the diaphragm,and it acts to open the valve I6 and release the brakes. The diaphragm,by means of an arm 3l is connected to a lever 32 by the pivot 33, andthe lower end of the lever is hinged or pivoted at 34 to a bracket 35rigid with the lower part of the valve casing.

The lever is pivotally connected at 31 to the free end 36 at the steml1.

The parts of the auxiliary control so far described are substantiallythe same as those identied by corresponding reference numerals in myprior Patent No. 2,183,444. The present improvement involves a departurefrom the previous device for controlling the operation of the servomotorS and consists of a suction pipe 39 having one end connected by acoupling 40 with the casing 30 at one side of the diaphragm 29. Theopposite end of the pipe 39 is branched at 39a-39b and connected with acylinder 50 at two axially spaced points. The piston is slidably mountedin the cylinder 56 and is provided with two grooves 52 and 53 spacedapart a distance less than the distance between the branches 39a and39h. At one end the cylinder is provided with a pressure equalizing vent54 communicating with the atmosphere and a rod 55 carried by the pistonprojects from the opposite end of the cylinder.

The cylinder is further provided with an atplane as the branch 39h sothat when the piston is moved to the left (Figure 3) communicationbetween the pipe branch 39h and the port 56 is established by the groove53. AV suction pipe 39e is connected at one end with the cylinder 5D ata point in the same circumferentialrplane as the pipe branch 39a so thatthe groove 52 connects the pipes 39a and 39.0 when the piston is in theposition shown in Figure 3.

The opposite end of the pipe 39o is connected with the intake manifold51 or other part of the fuel induction passage of the engine of themotor finger thereto the full effect of the suction existing in theintake manifold is exerted upon the piston 5| and the latter is moved tothe right as a consequence of the pressure differential existing betweenthe end of the cylinder that is open to atmosphere and the end thereofthat is in communication with the intake manifold through the pipe 59.

With the piston in the latter position the rod 55 is disposed inposition to be engaged by an arm 63 on the shaft 64 of the throttlevalve 58 as the latter moves from the closed position shown in Figure 4towards the open position upon depression of the usual accelerator, notshown. Thus during the initial open movement of .the throttle valves thepiston 5| is automatically moved from the right to the left handposition by fluid pressure, under manual control.

The cylinder 5!) is preferably disposed in a horizontal position so thatthe piston 5| is not influenced by gravity or any other force tending tomove it out of the position to which it has been moved within thecylinder as a result of the above described iluid pressure actuation bythe opening movement of the throttle valve 58.

Under normal conditions the piston 5| is in its left hand positionthereby establishing communication between the left side of the casing30 and the atmosphere through the atmospheric vent 56, groove 53, branch39h, pipe 39, and coupling 4I). In this condition of the auxiliarycontrol the valve I1 is maintained in open position by the spring 29'acting against the diaphragm 29 and the lever 32, consequently thebrakes of the vehicle may be hydraulically operated in the usual mannerunder control of the brake pedal 4. Also under these conditions the vent6| is open and unobstructed by the hand of the operator and the piston5| remains in the left hand position in the cylinder 59 due to its owninertia. When the applied brake pressure is to be retained in the brakecylinders the finger of the vehicle operator is momentarily applied tothe vent 6| to cap the same and hence the pressure diiferential existingbetween the opposite ends of the cylinder 50 is applied to the piston 5|through the vent 64 and the piston is caused to assume the right handposition shown in Figure 3 in which the atmospheric port 56 is closedand communication between the pipe 39e and the branch 39a and thus thepipe 39 is established by the groove 52. The pressure at the left sideof the diaphragm 29 is relieved through the communicating pipe 39 andthe ensuing displacement of said diaphragm oscillates the lever 32 andcloses the valve I1. In this manner communication through the brake pipe6 is interrupted and the brakes remain applied with the desired force.Naturally, the brakes are applied only when the engine throttle 58 isclosed, and consequently the arm 63 of the throttle valve is in suchpositionas to accommodate movement of the piston or controlV valve 5|toward the right. The piston is moved to the latter position by themomentary application of the finger of the ioperator to the vent 6| andthereafter the finger may be removed, the piston 5| remaining in theright hand position by its own inertia. To restore the piston 5l to theinoperative left hand position it is merely necessary for the operatorto slightly open the throttle valve 58 and is so doing the arm 63engages the rod 55 and shifts the piston to inoperative position.

Therefore, and as readily apparent from the drawings, I have provided ano-roll control for a motor vehicle that is under manual control to beautomatically actuated by fluid pressure means to hold the brakesapplied and which control is automatically moved to ineffective positionby manually operable means, the fluid pressure means relying on thepressure differential existing between the intake manifold and theatmosphere.

What I claim is:

1. In combination an engine manifold, a hydraulic brake system includinga pressure pipe leading to the brake cylinders, a normally open valve insaid pipe operable when closed to interrupt passage through said pipe, adifferential fluid pressure operated servo-motor for operating saidvalve, control means movable into different positions for alternatelyconnecting said servo-motor with atmosphere and the engine manifold,said control means being pressure sensitive and automatically movableinto one position under the iniiuence of the engine manifold vacuum andmanually controlled means affecting the pressure sensitivity of saidcontrol means so that said control means move into said position, andmanually controlled means for moving said control means into said otherposition.

2. In combination an engine manifold, a hydraulic brake system includinga pressure pipe leading to the brake cylinders, a normally open valve insaid pipe operable when closed to interrupt passage through said pipe tohold the brakes applied, a differential fluid pressure operatedservo-motor for operating said valve, control means movable intodifferent positions for alternately connecting said servo-motor withatmosphere and the engine manifold, said control means being pressuresensitive and automatically movable into one position under theinfluence of engine manifold vacuum to connect said servo motor with themanifold to close the valve, and manually controlled means for renderingsaid control means sensitive and movable into said valve closingposition.

3. In combination an engine manifold, a hydraulic brake system'including a pressure pipe leading to the brake cylinders, a normallyopen valve in said pipe operable when closed to interrupt passagethrough said pipe and hold the brakes applied, a differential fluidpressure operated servo-motor for operating said valve, control meansmovable into different positions for alternately connecting saidservo-motor with atmosphere and the engine manifold, said control meansbeing connected to the manifold and pressure sensitive under theinfluence of the vacuum existing therein to move into one position torender said servo motor capable of closing said valve and a. capableatmospheric vent communieating with said manifold by Way of said controlmeans and adapted when momentarily capped to render said control meanssensitive to pressure and the influence of the manifold vacuum.

4. In combination, an engine intake manifold and throttle valve, ahydraulic brake system including a pressure pipe leading to the brakecylinders, a, normally open valve in said pipe operable when closed tointerrupt passage through said pipe to hold the brakes applied, adifferential fluid pressure operated servo-motor for operating saidvalve, control means pressure sensitive to the influence of vacuumexisting in the manifold and movable into different positions foralternately connecting said servo-motor with atmosphere and the enginemanifold, manually controlled means affecting the pressure sensitivityof the control means so that the same automatically moves into oneposition, and means controlled by the throttle valve for positivelymoving the control means into another position.

5. An arrangement as claimed in claim 4 wherein said control means isconstituted by a cylinder and a piston movable therein.

6. An arrangement as claimed in claim 4 wherein said control meansincludes a cylinder and a piston movable therein an atmospheric vent forthe cylinder on one side of the piston, said manually controlled meansincluding a connection between the manifold and said cylinder on theopposite side of the piston and another connection between said cylinderand the atmosphere on the latter side of the piston, said last mentionedconnection being adapted to be momentarily capped to permit the pressuredifferential existing on opposite sides of the piston to move thecontrol means into the first mentioned position.

'7. An arrangement as claimed in claim 4 wherein said control meansincludes a cylinder and a piston movable therein, said throttle valvecontrolled means including a member connected to the throttle valve anddisposed exteriorly of the manifold and movable in a path in alignmentwith the piston and adapted to engage and move said piston into thesecond mentioned position when the throttle valve is opened.

8. In combination, an engine intake manifold, a throttle valve therein,a shaft for said throttle valve adapted to be rotatably moved underlniiuence of an accelerator pedal, a hydraulic brake system including apressure pipe leading to brake cylinders, a normally open valve in saidpipe operable when closed to interrupt passage through said pipe andhold the brakes applied, and manually controlled iiuid pressure operatedmeans lncluding a cylinder and a piston valve movable therein andrendered effective by momentary variation of fluid pressure in thecylinder to automatically move in one direction and maintain said firstmentioned valve in closed position, said iluid pressure operated meansproviding alternate communication between said manifold and theatmosphere and operable when vented to atmosphere to open said firstmentioned valve to release the brakes, and means connected to thethrottle valve shaft and operable when moved thereby when theaccelerator pedal is depressed to contact said piston valve and move thesame in an opposite direction to vent said fluid pressure operated meansto atmosphere.

DOUGLAS COLLINS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,080,295 Wheeler May 11. 193'12,183,444 Collins Dec. 12, 1939 2,201,125 Freeman May 11, 1940 2,224,747Sacks Dec. 10, 1940 2,313,430 Goepfrich Mar. 9, 1943

